America's economy and future security will rely on the country's ability to tackle climate change, Republican presidential candidate John McCain has said.
The former Vietnam prisoner of war criticised President George Bush for backing away from the Kyoto global warming protocols in a key speech on global warming and said that as president he would return to the negotiating table.
Mr McCain also said he would introduce a cap-and-trade system for carbon emissions, aiming to reduce them to a level 60% below that emitted in 1990 by 2050, and added that nuclear energy was a "powerful ally" as the US moved towards this goal.
The 71-year-old Arizona senator laid out his plans at the home of a wind technology plant in Portland, Oregon, as his Democrat rivals Barack Obama and Hillary Clinton were preparing for tomorrow's primary election contest in West Virginia.
He said many alternative energy sources were "changing our economy for the better" and added: "One day they will change our economy forever.
"Our economy depends upon clean and affordable alternatives to fossil fuels, and so, in many ways, does our security."
He went on: "The facts of global warming demand our urgent attention, especially in Washington.
"We have many advantages in the fight against global warming, but time is not one of them. We stand warned by serious and credible scientists across the world that time is short and the dangers are great."
Mr McCain said he would "draw on the best ideas of both parties" and added: "You would think that if the polar bears, walruses and sea birds have the good sense to respond to new conditions and new dangers, then humanity can respond as well.
"Global warming presents a test of foresight, of political courage, and of the unselfish concern that one generation owes to the next."